Feasibility study for future spaceborne coherent Doppler wind lidar,part 2: Measurement simulation algorithms and retrieval error characterization

A feasibility study of tropospheric wind measurements using a coherent doppler lidar aboard a super low altitude satellite is being conducted in japan. the considered lidar uses a 2.05 µm laser light source of 3.75 w. in order to assess the measurement performances,simulations of wind measurements were conducted. the mission definition is presented in a companion paper (part 1) while,in this paper,we describe the measurement simulator and characterize the errors on the retrieved line-of-sight (los) winds. winds are retrieved from the doppler-shift of the noisy backscattered signal with a horizontal resolution of 100 km along the orbit track and a vertical resolution between 0.5 and 2 km. cloud and wind fields are the pseudo-truth of an observing system simulation experiment while aerosol data are from the model-of-aerosol-species-in-the global-atmosphere (masingar) constrained with the pseudo-truth wind. we present the results of the analysis of a full month of data in summer time for a near-polar orbiting satellite and a los nadir angle of35°. below ≈ 8 km,the ratio of good retrievals is 30 - 55 % and the median los wind error is better than 0.6 m s-1 (1.04 m s-1 for the horizontal wind). in the upper troposphere,the ratio is less than 15 % in the southern hemisphere and high-latitudes. however,the ratio is still 35 % in the northern tropics and mid-latitudes where ice-clouds frequently occur. the upper-tropospheric median los-wind measurement error is between 1 - 2 m s-1 depending on the latitude (1.74 - 3.5 m s-1 for the horizontal wind). these errors are dominated by uncertainties induced by spatial atmospheric inhomogeneities. ©2017,meteorological society of japan. all rights reserved.